Monthly Archives: March 2013

So, I need some help. I have some really fun data. It shows, for every minute during the Birkie, how many skiers were at each quarter kilometer of the course. The example above, for instance, shows the state of the race—the actual position of skiers on the course, by wave—at 9:03 a.m.. The fourth wave is just setting out while the earliest waves are already forming packs. The front of the third wave is catching the front of the second; the front of the second wave is making progress in to the first. Pretty cool, right? (These are all based on four split times, so it’s not a perfect representation of exactly who is where, but it’s a pretty good approximation.)

I want to animate these, probably in to a Youtube or Vimeo and play it at, say, 5–10 fps (so each hour is 6–12 seconds and the whole of the race takes a minute or two). But there are (at least) two relatively major stumbling blocks, and if anyone can help, I’d certainly be grateful:

I need to export 600 images. One for each minute, 8 a.m. to 6 p.m. I certainly could do this manually, but I would be driven to the drink well before the first wave arrived in Hayward. In other words, I need to automate this. I think it could be done in Excel; you’d need a Macro to find a piece of text, increment it, export the chart and loop back to the beginning. (Why the find-replace? The method I used to get the data was to calculate the position for each racer for each minute. I then ran a separate count for the number of skiers in each 250m block for a particular minute and made a chart. Then I run a Find-Replace to go from, for instance, cell AB to cell AC which increments one minute forward. If anyone has a better idea how to do this in Excel or in a SQL environment, I’m all ears.)

Take all these images in to some kind of video-making program and compress it in to a “time lapse” thing. I think I know someone who can do this, but if anyone has those skills, and if we get to that point, I’d be very happy for the help.

If you can provide any assistance, it would be fantastic. Drop me an email (ari.ofsevit@gmail) or comment here (you need to log in; otherwise we get lots of spam) to get in touch. Extra bonus points if you’re patient enough to explain to me what you’re doing, instead of just doing it. I’d certainly give you lots of on-site recognition for any help, and probably buy you a beer in Hayward next February.

An obscure Simpsons quote notwithstanding, it’s time for me to brush up on Unix time. Why? Because I have a dataset with close to 20,000 rows of Birkie data, and the split times are in Unix time. It’s exact, yes, but kind of kooky to sort in to real-life time.

In any case, look for data updates in coming days. Data!

Updates: we’re getting some really fun data for the number of people each skier passed and was passed by, split data, and the like. Stay tuned!

In the northeast, there is skiing to be had. A surprise foot-and-a-half of snow last week prolonged the season; I’m slated to ski a 50k later this week. Last year, it was the last day of skiing, as the snow melted off the course during the race. It was followed by a week of temperatures in the 70s and 80s (!) which melted every last bit of snow in New England. In the midwest, reports are that there is skiable snow on the trails, with perhaps more to come. Duluth has two feet on the ground, and the UP may not melt until June. (And there’s no 2012-style week-in-the-70s coming there, either.)

This is all well and good, since I still don’t have results from the Birkie and there are still discrepancies. So, keep on skiing, and we’ll have data to pore over once the snow melts and you can sit outside with a mai tai and get a tan (July). And are we going to compare fat bike results with ski results? Will the new Pope be Catholic?